Interpretive Summary: Beekeepers are concerned about the current performance of their queen bees. We examined the possibility that the presence of parasitic mites in colonies was affecting the quality of the drones with which the queens mate. We found that while drones from mite-infested and uninfested colonies produced normal volumes of semen with the usual concentration of live sperm, fewer mite-infested drones lived to the age of mating. This information will be used by beekeepers to ensure sufficient numbers of drones in mating areas.

Technical Abstract:
Varroa infestation in a colony is a factor in the production of sufficient, high-quality drones for mating. Using a staining technique that distinguishes between live and dead sperm, we determined that both normal drones and those parasitized by varroa during pupation, produce similar volumes of semen, and similar concentrations and viability of spermatozoa. However, the numbers of drones that live to the age of reproductive maturity is reduced when varroa were found in the cells. Queen producers should be aware of this reduced drone population and adjust colony numbers accordingly.